1. Field of the Invention
This invention relates to the field of foundation supports for buildings and other structures. More particularly, this invention relates to improvements in sectional piles.
2. Description of the Prior Art
Many structures have been built on foundations or slabs made of concrete poured on top of soil. Constant changes in the weather and moisture levels in the soil frequently cause damage to such a foundation. In many instances, the foundation may buckle or even crack.
This phenomenon occurs because prior to placing the foundation on the ground, the moisture beneath it is constant. Placing a foundation on the soil distorts the evaporation of the moisture underneath the foundation, thereby causing water buildup and relative soil swelling in the middle of the structure. Eventually, an uplifting can occur in the center because the moisture from around the edges of the structure relative to the center is drawn away by evaporation and/or by wicking action of the adjacent shrubbery or plant life. Over a period of time the foundation can "dome," causing damage or failure.
There are several methods used in repairing foundations. One of the most effective and widely used methods includes the use of one or more piles submerged into the soil beneath the foundation to form one or more supports. Most of the supports are made primarily of concrete and have an overall cylindrical shape with a length varying according to the soil type and the weight of the structure. For clarity, the words "piling section" and "section" signify a single cylindrical piece, and the words "pile" and "piling" signify a plurality of sequentially stacked pieces (sections) to form a single support column. A plurality of piles or pilings then provide overall load support for a structure in the form of a piling system.
One of the most successful foundation rehabilitation procedures involves excavating, or partially excavating, underneath the grade beams that need to be supported or raised, placing a concrete piling section in the excavated cavity underneath the grade beam, placing a construction jack between the grade beam and the piling section, and then operating the jack by hydraulic or pneumatic action to force the piling section downward into the ground while supporting the grade beam. Once the piling section is driven sufficiently into the ground so that its top is flush with the bottom of the excavated area, another piling section is put in place on top of the previous piling section and the jack is reactivated. Eventually, either the piling made up of the piling sections will hit bedrock or the ground underneath and surrounding the piling will become so compacted as to make further piling section additions unnecessary.
When a concrete piling of extended length formed by axially coupling a number of piling sections is driven in place, even slight differences in axial alignment between the sections will result in a large axial deflection in the pile at its lower, leading end. Known pile joint and coupling devices permit varying degrees of tolerance in the alignment of the piling sections. The piling sections are thus subjected to a broad range of bending stresses when the piling is loaded with the grade beams. As such, there remains a need in foundation construction for easily assembled, precision aligned piling sections.
Accordingly, it is an object of the present invention to provide a piling with precision axial alignment of its piling sections. This and other objects and advantages of the present invention will be evident from the following drawings, specifications and claims.